HANA "Select for update" through JDBC: CONCUR_UPDATABLE result set concurrency is considered invalid

I am in the process of trying to use HANA as persistence layer for our application.

For this I am using the AWS image “ami-68bf1d1b” to run the HANA database.

I have been running our database test that verifies we adequately generate the SQL needed for our application for each database we support.

This test passes on all the other SQL databases our software already supports: Derby, Sqlite, mySql, SQLServer, Oracle and Postgresql.

It creates a table, inserts some records, performs some updates then updates some rows through a “select for update”. (The “?” are placeholders filled with values through JDBC.)

DatabaseTest/2016-02-22 11:01:22 info:create table TEST_TBL79960 (ID VARCHAR(10), DATA BLOB, AMOUNT DOUBLE, primary key (ID))

DatabaseTest/2016-02-22 11:01:23 info:insert into TEST_TBL79960 (ID, DATA, AMOUNT) values (?, ?, ?)

DatabaseTest/2016-02-22 11:01:23 info:update TEST_TBL79960 set DATA = ?, AMOUNT = ? where ID = ?

DatabaseTest/2016-02-22 11:01:24 info:select ID, DATA, AMOUNT from TEST_TBL79960 where ID = ? for update

It did fail when executing the “select for update” with the following exception:.

com.sap.db.jdbc.exceptions.jdbc40.SQLDataException: Invalid argument resultSetConcurrency, use CONCUR_READ_ONLY.

at com.sap.db.jdbc.exceptions.jdbc40.SQLDataException.createException(SQLDataException.java:40)

at com.sap.db.jdbc.exceptions.SQLExceptionSapDB.createException(SQLExceptionSapDB.java:278)

at com.sap.db.jdbc.exceptions.SQLExceptionSapDB.generateSQLException(SQLExceptionSapDB.java:146)

at com.sap.db.jdbc.StatementSapDB.<init>(StatementSapDB.java:114)

at com.sap.db.jdbc.CallableStatementSapDB.<init>(CallableStatementSapDB.java:88)

at com.sap.db.jdbc.CallableStatementSapDBFinalize.<init>(CallableStatementSapDBFinalize.java:31)

at com.sap.db.jdbc.ConnectionSapDB.prepareStatement(ConnectionSapDB.java:1287)

at com.sap.db.jdbc.trace.Connection.prepareStatement(Connection.java:355)

at ides.core.tools.sql.Database.select(Database.java:526)

at ides.app.tools.sql.DatabaseTest.test(DatabaseTest.java:278)

at ides.app.tools.sql.DatabaseTest.testHana(DatabaseTest.java:147)

This test is done after having verified that the database supports “select for update”:

Connection connection = …; // obtain connection to HANA

DatabaseMetaData metaData = connection.getMetaData();

metaData.supportsSelectForUpdate(); // HANA returns true

The select statement itself is executed with:

PreparedStatement selectForUpdate = connection.prepareStatement(sql, ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_UPDATABLE);

selectForUpdate.setString(1, "test");

ResultSet resultSet = selectForUpdate.executeQuery();

We specify “ResultSet.CONCUR_UPDATABLE” because we want to set values in the obtained result set - that is the whole point of having used a “select for update”.

If I change the code as indicated by the HANA exception above:

PreparedStatement selectForUpdate = connection.prepareStatement(sql, ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);

selectForUpdate.setString(1, "test");

ResultSet resultSet = selectForUpdate.executeQuery();

Then the HANA JDBC driver raises the following exception when trying to update the content of the result set:

com.sap.db.jdbc.exceptions.JDBCDriverException: SAP DBTech JDBC: Result set is not updatable.

at com.sap.db.jdbc.exceptions.SQLExceptionSapDB.createException(SQLExceptionSapDB.java:374)

at com.sap.db.jdbc.exceptions.SQLExceptionSapDB.generateSQLException(SQLExceptionSapDB.java:113)

at com.sap.db.jdbc.ResultSetSapDB.throwNotUpdatable(ResultSetSapDB.java:2837)

at com.sap.db.jdbc.ResultSetSapDB.updateBytes(ResultSetSapDB.java:1666)

at com.sap.db.jdbc.trace.ResultSet.updateBytes(ResultSet.java:1260)

at ides.app.tools.sql.DatabaseTest.test(DatabaseTest.java:285)